weird problem with c++ libraries and symbols

weird problem with c++ libraries and symbols

[Ottavio Campana]

Hi!

I am facing a weird problem with a c++ library and after having googled
for a while I'm asking here for a suggestion.

In the last months, I developed an application in C. This application
consists of several libraries and programs. Everything is written in C
with the exception of the library handling RTSP streaming, which uses
livemedia ( http://www.live555.com/liveMedia/ ) to do all the protocol
stuff, which is written in C++, but the RTSP library I wrote was meant
to be used only by C programs.

LiveMedia provides some makefiles that compile the 4 provided libraries
as static libraries, and I statically linked these .a files into my
final .so and everything worked.

Now I have to expand my application and I need to use the libraries
provided by livemedia also in another program, so I decided to try and
write my own makefile by using autotools to get four .so libraries that
I can reuse them in different applications.

I build the for libraries of livemedia and my own library which depends
on the previous four and I expect that by linking all the libraries to
the binary everything should work, but it does not.

The problem that I'm facing is that some symbols from the livemedia
libraries are undefined, I tried to solve it in different ways but I ran
out of ideas.

Here are my thoughts:

* can it be the fact that I'm mixing C and C++? It seems that the
unresolved symbols are due to virtual and static functions and not to
name mangling

* I tried to add all the files of the livemedia library to the sources
of my dynamic library, so that I could have one big library instead of
5, but the problem persists.

* I complied again manually the static libraries and added them to my
dynamic library. It works, but I don't understand why and I cannot
understand why the previous case does not. Is it a problem due to autotools?

* I tried to use -fvisibility with different values, with no luck.

I'm not expert of C++, so surely I made a mistake, but I haven't been
able to understand where it is. Did you ever face a similar problem? Or
do you have a hint for me? I wrong this long email trying to clearly
explain my problem.

Thank you for any answer in advance,

Ottavio

Re: weird problem with c++ libraries and symbols

[Jonathan Wakely]

On 29 September 2011 13:28, Ottavio Campana wrote:
>
> I am facing a weird problem with a c++ library and after having googled
> for a while I'm asking here for a suggestion.

You might get better answers if you provide the compiler and linker
commands you're using to create the shared libraries and (some of) the
errors you get, as it will show if you're missing out anything
important and give a clue about which type of symbols are missing.

Re: weird problem with c++ libraries and symbols

[Ottavio Campana]

On 09/29/2011 02:54 PM, Jonathan Wakely wrote:
> On 29 September 2011 13:28, Ottavio Campana wrote:
>>
>> I am facing a weird problem with a c++ library and after having googled
>> for a while I'm asking here for a suggestion.
> 
> You might get better answers if you provide the compiler and linker
> commands you're using to create the shared libraries and (some of) the
> errors you get, as it will show if you're missing out anything
> important and give a clue about which type of symbols are missing.

Ok I try, but it's really a lot of stuff.

If I use nm, I see a lot of undefined symbols, such as

nm -DC .libs/libgroupsock.so

                 w _Jv_RegisterClasses
                 U _Unwind_Resume
                 U readSocket(UsageEnvironment&, int, unsigned char*,
unsigned int, sockaddr_in&)
                 U writeSocket(UsageEnvironment&, int, in_addr, Port,
unsigned char, unsigned char*, unsigned int)
                 U ourIPAddress(UsageEnvironment&)
                 U getSourcePort(UsageEnvironment&, int, Port&)
                 U socketJoinGroup(UsageEnvironment&, int, unsigned int)
                 U timestampString()
                 U socketLeaveGroup(UsageEnvironment&, int, unsigned int)
0000000000005610 T socketReadHandler(Socket*, int)
                 U IsMulticastAddress(unsigned int)
                 U socketJoinGroupSSM(UsageEnvironment&, int, unsigned
int, unsigned int)
                 U socketLeaveGroupSSM(UsageEnvironment&, int, unsigned
int, unsigned int)
                 U strDup(char const*)
0000000000003b30 T destRecord::destRecord(in_addr const&, Port const&,
unsigned char, destRecord*)

But for example readSocket is implemented in
groupsock/GroupsockHelper.cpp . I don't think it's normal.


This is the generation of librtsp.so, which is my library

libtool: link: g++ -shared -nostdlib
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o  .libs/librtsp_la-rtsp.o
.libs/queue.o .libs/librtsp_la-VT_JPEGVideoSource.o
.libs/librtsp_la-VT_JPEGVideoRTPSource.o
.libs/librtsp_la-VT_MediaSession.o .libs/librtsp_la-VideoDeviceSource.o
.libs/librtsp_la-AudioDeviceSource.o
.libs/librtsp_la-DetectionDeviceSource.o
.libs/librtsp_la-VideoOnDemandServerMediaSubsession.o
.libs/librtsp_la-DetectionOnDemandServerMediaSubsession.o
.libs/librtsp_la-VT_H264VideoStreamFramer.o
.libs/librtsp_la-VT_DetectionFileServerMediaSubsession.o
.libs/librtsp_la-VT_RTSPServer.o .libs/librtsp_la-VT_Sink.o
.libs/base64.o   -Wl,-rpath
-Wl,/home/ottavio/Projects/albert/src/protocols/rtsp/.libs -Wl,-rpath
-Wl,/opt/lib -lpthread ./.libs/libUsageEnvironment.so
./.libs/libBasicUsageEnvironment.so ./.libs/libgroupsock.so
./.libs/libliveMedia.so -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
-L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
-Wl,-soname -Wl,librtsp.so.1 -o .libs/librtsp.so.1.0.0


These are libliveMedia.so, libgroupsock.so , libUsageEnvironment.so and
libBasicUsageEnvironment.so which are the four libraries of liveMedia


libtool: link: g++ -shared -nostdlib
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o
.libs/libliveMedia_la-MPEGVideoStreamFramer.o
.libs/libliveMedia_la-AC3AudioStreamFramer.o
.libs/libliveMedia_la-DarwinInjector.o .libs/libliveMedia_la-our_md5.o
.libs/libliveMedia_la-AMRAudioFileSource.o
.libs/libliveMedia_la-ServerMediaSession.o
.libs/libliveMedia_la-AMRAudioFileServerMediaSubsession.o
.libs/libliveMedia_la-Base64.o .libs/libliveMedia_la-JPEGVideoSource.o
.libs/libliveMedia_la-MP3ADUinterleaving.o
.libs/libliveMedia_la-H264VideoFileServerMediaSubsession.o
.libs/libliveMedia_la-MPEG1or2FileServerDemux.o
.libs/libliveMedia_la-MP3ADURTPSource.o
.libs/libliveMedia_la-H264VideoRTPSink.o
.libs/libliveMedia_la-MPEG2TransportStreamTrickModeFilter.o
.libs/libliveMedia_la-AudioRTPSink.o
.libs/libliveMedia_la-MPEG2TransportFileServerMediaSubsession.o
.libs/libliveMedia_la-WAVAudioFileServerMediaSubsession.o
.libs/libliveMedia_la-MediaSink.o
.libs/libliveMedia_la-MPEG1or2DemuxedElementaryStream.o
.libs/libliveMedia_la-H261VideoRTPSource.o
.libs/libliveMedia_la-BasicUDPSource.o
.libs/libliveMedia_la-MP3AudioFileServerMediaSubsession.o
.libs/libliveMedia_la-RTSPServerSupportingHTTPStreaming.o
.libs/libliveMedia_la-MPEGVideoStreamParser.o
.libs/libliveMedia_la-ADTSAudioFileSource.o
.libs/libliveMedia_la-DeviceSource.o
.libs/libliveMedia_la-DVVideoRTPSink.o
.libs/libliveMedia_la-MP3ADUdescriptor.o
.libs/libliveMedia_la-MP3Internals.o
.libs/libliveMedia_la-H263plusVideoStreamFramer.o
.libs/libliveMedia_la-BitVector.o
.libs/libliveMedia_la-QCELPAudioRTPSource.o
.libs/libliveMedia_la-H263plusVideoRTPSink.o
.libs/libliveMedia_la-MP3FileSource.o
.libs/libliveMedia_la-H264VideoRTPSource.o
.libs/libliveMedia_la-MPEG1or2DemuxedServerMediaSubsession.o
.libs/libliveMedia_la-ByteStreamMultiFileSource.o
.libs/libliveMedia_la-our_md5hl.o
.libs/libliveMedia_la-SimpleRTPSource.o
.libs/libliveMedia_la-MP3ADURTPSink.o
.libs/libliveMedia_la-MP3InternalsHuffman.o
.libs/libliveMedia_la-JPEGVideoRTPSource.o
.libs/libliveMedia_la-JPEGVideoRTPSink.o
.libs/libliveMedia_la-AMRAudioRTPSource.o
.libs/libliveMedia_la-MPEG4VideoFileServerMediaSubsession.o
.libs/libliveMedia_la-OutputFile.o
.libs/libliveMedia_la-MPEG1or2AudioRTPSource.o
.libs/libliveMedia_la-RTPSource.o
.libs/libliveMedia_la-PassiveServerMediaSubsession.o
.libs/libliveMedia_la-FramedFileSource.o
.libs/libliveMedia_la-MPEG1or2VideoStreamDiscreteFramer.o
.libs/libliveMedia_la-H263plusVideoStreamParser.o
.libs/libliveMedia_la-QuickTimeFileSink.o
.libs/libliveMedia_la-MPEG2TransportStreamFromESSource.o
.libs/libliveMedia_la-MediaSource.o
.libs/libliveMedia_la-MPEG1or2VideoRTPSink.o
.libs/libliveMedia_la-AVIFileSink.o
.libs/libliveMedia_la-MultiFramedRTPSink.o
.libs/libliveMedia_la-MPEG1or2VideoStreamFramer.o
.libs/libliveMedia_la-MPEG4GenericRTPSource.o
.libs/libliveMedia_la-AMRAudioRTPSink.o
.libs/libliveMedia_la-AMRAudioFileSink.o
.libs/libliveMedia_la-FramedFilter.o
.libs/libliveMedia_la-H263plusVideoFileServerMediaSubsession.o
.libs/libliveMedia_la-BasicUDPSink.o
.libs/libliveMedia_la-MPEG1or2AudioRTPSink.o
.libs/libliveMedia_la-MediaSession.o
.libs/libliveMedia_la-MPEG4LATMAudioRTPSink.o
.libs/libliveMedia_la-MP3HTTPSource.o
.libs/libliveMedia_la-DVVideoRTPSource.o
.libs/libliveMedia_la-RTPInterface.o
.libs/libliveMedia_la-SimpleRTPSink.o
.libs/libliveMedia_la-MPEG1or2VideoRTPSource.o
.libs/libliveMedia_la-H263plusVideoRTPSource.o
.libs/libliveMedia_la-MPEG1or2Demux.o
.libs/libliveMedia_la-AudioInputDevice.o
.libs/libliveMedia_la-MPEG1or2VideoFileServerMediaSubsession.o
.libs/libliveMedia_la-RTSPCommon.o
.libs/libliveMedia_la-FileServerMediaSubsession.o
.libs/libliveMedia_la-InputFile.o .libs/libliveMedia_la-RTPSink.o
.libs/libliveMedia_la-MP3ADU.o .libs/libliveMedia_la-RTCP.o
.libs/libliveMedia_la-MultiFramedRTPSource.o
.libs/libliveMedia_la-FramedSource.o .libs/libliveMedia_la-Media.o
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
-L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
-Wl,-soname -Wl,libliveMedia.so.2009 -o .libs/libliveMedia.so.2009.2.9


libtool: link: g++ -shared -nostdlib
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o
.libs/libgroupsock_la-Groupsock.o .libs/libgroupsock_la-GroupEId.o
.libs/libgroupsock_la-IOHandlers.o
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
-L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
-Wl,-soname -Wl,libgroupsock.so.2009 -o .libs/libgroupsock.so.2009.2.9


libtool: link: g++ -shared -nostdlib
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o
.libs/libUsageEnvironment_la-UsageEnvironment.o
.libs/libUsageEnvironment_la-strDup.o
.libs/libUsageEnvironment_la-HashTable.o
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
-L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
-Wl,-soname -Wl,libUsageEnvironment.so.2009 -o
.libs/libUsageEnvironment.so.2009.2.9


libtool: link: g++ -shared -nostdlib
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o
.libs/libBasicUsageEnvironment_la-BasicUsageEnvironment.o
.libs/libBasicUsageEnvironment_la-BasicUsageEnvironment0.o
.libs/libBasicUsageEnvironment_la-DelayQueue.o
.libs/libBasicUsageEnvironment_la-BasicTaskScheduler0.o
.libs/libBasicUsageEnvironment_la-BasicTaskScheduler.o
.libs/libBasicUsageEnvironment_la-BasicHashTable.o
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
-L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
-L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
-Wl,-soname -Wl,libBasicUsageEnvironment.so.2009 -o
.libs/libBasicUsageEnvironment.so.2009.2.9


And that's when I try to link all together, I just post a few errors


libtool: link: gcc -g -O2 -Wall -D_GNU_SOURCE -I../../protocols/rtsp/
-I../../protocols/common/ -I../common/ -I../agent/ -g -O2 -o
.libs/rtsp_proxy rtsp_proxy-main.o rtsp_proxy-variables.o
rtsp_proxy-base64.o rtsp_proxy-queue.o rtsp_proxy-posix_queue.o
../../protocols/rtsp/.libs/librtsp.so
../../protocols/rtsp/.libs/libBasicUsageEnvironment.so
../../protocols/rtsp/.libs/libUsageEnvironment.so
../../protocols/rtsp/.libs/libgroupsock.so
../../protocols/rtsp/.libs/libliveMedia.so -Wl,-rpath -Wl,/opt/lib
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`AMRAudioSource::~AMRAudioSource()'
../../protocols/rtsp/.libs/librtsp.so: undefined reference to
`RTSPServer::setUpOurSocket(UsageEnvironment&, Port&)'
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`AMRAudioSource::isAMRAudioSource() const'
../../protocols/rtsp/.libs/libgroupsock.so: undefined reference to
`our_inet_ntoa'
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`StreamParser::~StreamParser()'
../../protocols/rtsp/.libs/libgroupsock.so: undefined reference to
`DirectedNetInterfaceSet::Iterator::next()'
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`increaseReceiveBufferTo(UsageEnvironment&, int, unsigned int)'
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`uLawFromPCMAudioSource::createNew(UsageEnvironment&, FramedSource*, int)'
../../protocols/rtsp/.libs/libliveMedia.so: undefined reference to
`RTSPClient::isRTSPClient() const'
...
...




Thank you,

Ottavio

Re: weird problem with c++ libraries and symbols

[Jonathan Wakely]

On 29 September 2011 14:36, Ottavio Campana wrote:
> On 09/29/2011 02:54 PM, Jonathan Wakely wrote:
>> On 29 September 2011 13:28, Ottavio Campana wrote:
>>>
>>> I am facing a weird problem with a c++ library and after having googled
>>> for a while I'm asking here for a suggestion.
>>
>> You might get better answers if you provide the compiler and linker
>> commands you're using to create the shared libraries and (some of) the
>> errors you get, as it will show if you're missing out anything
>> important and give a clue about which type of symbols are missing.
>
> Ok I try, but it's really a lot of stuff.

But it makes it much more likely someone can see a problem.

Another option is asking the LiveMedia developers list, as it's
unlikely your problem is caused by GCC and someone there might have
tried what you're doing.

Re: weird problem with c++ libraries and symbols

[Ottavio Campana]

Il 29/09/2011 17:36, Jonathan Wakely ha scritto:
> On 29 September 2011 14:36, Ottavio Campana wrote:
>> On 09/29/2011 02:54 PM, Jonathan Wakely wrote:
>>> On 29 September 2011 13:28, Ottavio Campana wrote:
>>>>
>>>> I am facing a weird problem with a c++ library and after having googled
>>>> for a while I'm asking here for a suggestion.
>>>
>>> You might get better answers if you provide the compiler and linker
>>> commands you're using to create the shared libraries and (some of) the
>>> errors you get, as it will show if you're missing out anything
>>> important and give a clue about which type of symbols are missing.
>>
>> Ok I try, but it's really a lot of stuff.
> 
> But it makes it much more likely someone can see a problem.
> 
> Another option is asking the LiveMedia developers list, as it's
> unlikely your problem is caused by GCC and someone there might have
> tried what you're doing.

I know, it has already been discussed in the past there, but only static
library are officially supported. The author does not exclude that it
can be done, but he does not give support.

Is it possible to write a library that works only if compiled
statically? This would be the first time for me that I'd see such a code...

Ottavio

Re: weird problem with c++ libraries and symbols

[Ian Lance Taylor]

Ottavio Campana <ottavio@videotec.com> writes:

> If I use nm, I see a lot of undefined symbols, such as
>
> nm -DC .libs/libgroupsock.so

>                  U readSocket(UsageEnvironment&, int, unsigned char*,
> unsigned int, sockaddr_in&)

> But for example readSocket is implemented in
> groupsock/GroupsockHelper.cpp . I don't think it's normal.

> libtool: link: g++ -shared -nostdlib
> /usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crti.o
> /usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtbeginS.o
> .libs/libgroupsock_la-Groupsock.o .libs/libgroupsock_la-GroupEId.o
> .libs/libgroupsock_la-IOHandlers.o
> -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5
> -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib -L/lib/../lib
> -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../..
> -L/usr/lib/x86_64-linux-gnu -lstdc++ -lm -lc -lgcc_s
> /usr/lib/gcc/x86_64-linux-gnu/4.4.5/crtendS.o
> /usr/lib/gcc/x86_64-linux-gnu/4.4.5/../../../../lib/crtn.o
> -Wl,-soname -Wl,libgroupsock.so.2009 -o .libs/libgroupsock.so.2009.2.9

The command which creates libgroupsock.so is not including
GroupsockHelper, so it seems unsurprising that the .so does not define
readSocket.

Ian

Re: weird problem with c++ libraries and symbols

[Ottavio Campana]

On 09/29/2011 09:05 PM, Ian Lance Taylor wrote:
> The command which creates libgroupsock.so is not including
> GroupsockHelper, so it seems unsurprising that the .so does not define
> readSocket.

doh! It was a missing \ in Makefile.am, thus a bunch of files were not
compiled in the library...

It works now, thank you a lot for the suggestion!

Ottavio